Prinzmetal angina is a form of unstable angina caused by transient coronary artery vasospasm, resulting in transmural ischemia with characteristic ST-segment elevation that resolves spontaneously or with nitroglycerin, typically without progression to MI. [1-2] It can occur with normal coronary arteries, nonobstructive CAD, or superimposed on obstructive CAD. [1-2]
The following figure demonstrates angiographic documentation of coronary vasospasm with associated ECG changes and resolution after intracoronary nitroglycerin:
1. History
- Chest pain at rest, classically occurring between midnight and early morning (circadian pattern) [2]
- Substernal pressure/squeezing, similar to typical angina but occurring without exertion
- Episodes are typically brief (minutes), self-resolving or rapidly relieved by sublingual NTG [1]
- May be precipitated by emotional stress, hyperventilation, exercise, or cold exposure [2]
- Ask about smoking, cocaine, methamphetamine, marijuana use [4-5]
- Ask about medication exposures: 5-fluorouracil, paclitaxel, sumatriptan, pseudoephedrine [4-5]
- Episodic and recurrent nature — may cluster in waves with symptom-free intervals
- Important negatives: absence of exertional pattern, absence of progressive crescendo
2. Alarm Features
- Syncope — suggests life-threatening arrhythmia (VT, VF, high-degree AV block) [6-7]
- Prolonged chest pain (>15–20 min) — risk of progression to MI
- Documented malignant arrhythmias during spontaneous attacks carry a 42% risk of sudden death within 26 months vs 6% without arrhythmias [6]
- Hemodynamic instability, cardiac arrest
- Lambda wave pattern on ECG — high-risk marker for lethal arrhythmias [6]
- New heart failure symptoms suggesting ischemic cardiomyopathy from recurrent spasm
3. Medications
First-line treatment
- Calcium channel blockers (CCBs) — cornerstone therapy (Class I, AHA/ACC) [1-2][8]
- Verapamil 240–480 mg/day
- Diltiazem 180–360 mg/day
- Nifedipine/amlodipine 60–120 mg/day (nifedipine)
- Sublingual NTG for acute episodes — exquisitely effective [1]
- Long-acting nitrates (isosorbide mononitrate) as add-on; benefit is debated due to tolerance concerns [5][9]
Second-line / adjunctive
- Statins — improve endothelial vasodilation (Class I) [2]
- Magnesium supplementation [2]
- Alpha-receptor blockers — for refractory cases [1-2]
- Cilostazol, nicorandil (not available in the US), fasudil [5][8-9]
- Refractory disease: combination of two CCB classes (dihydropyridine + non-dihydropyridine) [1][8]
Contraindicated / use with caution
- Beta-blockers — may worsen spasm via unopposed alpha-adrenergic activity [1][5][10]
- Aspirin — may contribute to vasospasm via prostacyclin inhibition; DAPT associated with worse outcomes in vasospastic angina without significant CAD [5]
- Cocaine, amphetamines — must be discontinued [5][7]
4. Diet
- Smoking cessation is the single most impactful lifestyle modification (Class I) [2][9]
- Alcohol moderation — alcohol intake abatement recommended [11]
- Magnesium-rich foods may be beneficial (leafy greens, nuts, seeds)
- Avoid stimulant-containing supplements (ephedra, high-dose caffeine)
- Stress reduction strategies (meditation, exercise) — emotional stress is a known trigger [2]
5. Review of Systems
- Cardiovascular: palpitations, syncope/presyncope, dyspnea, diaphoresis
- Neurologic: migraine history — vasospastic angina has a suggested correlation with migraines [11]
- Psychiatric: emotional stress, panic attacks (can mimic or trigger episodes)
- Pulmonary: hyperventilation (trigger for spasm) [2]
- Allergic/immunologic: history of allergic reactions — Kounis syndrome (allergic angina) is a recognized entity [7]
6. Collateral History and Family History
- Family history of vasospastic angina — recent Swedish nationwide study demonstrated high familial heritability [11]
- RNF213 gene variants (particularly p.R4810K) associated with vasospastic angina and fatal MI, especially in East Asian populations [11]
- Social history: detailed substance use history (cocaine, methamphetamine, marijuana, tobacco) [4-5]
- Occupational cold exposure
- Medication list from pharmacy/family — identify vasoconstrictive agents
7. Risk Factors
- Smoking — the most prominent coronary risk factor for vasospastic angina [2][4]
- Cocaine and methamphetamine use [4-5]
- East Asian ethnicity — significantly higher prevalence (up to 40% of angina patients in Japan) [8][11]
- Female sex — variant angina more common among women; younger women (<50) with vasospastic angina have worse long-term prognosis [4][7]
- Chemotherapy agents: 5-fluorouracil, paclitaxel [4]
- Medications: sumatriptan, pseudoephedrine, inotropes [5]
- Emotional stress, hyperventilation [2]
- Myocardial bridging — independent predictor of LAD-specific vasospasm [12]
8. Differential Diagnosis
- STEMI / acute coronary syndrome — the most critical cannot-miss diagnosis; transient STE in Prinzmetal resolves completely, whereas STEMI progresses [1]
- Takotsubo cardiomyopathy — stress-induced, apical ballooning, can have STE
- Myocarditis / pericarditis — diffuse STE, PR depression, troponin elevation
- Aortic dissection — tearing pain, pulse deficits, widened mediastinum
- Pulmonary embolism — dyspnea-predominant, right heart strain pattern
- Microvascular angina (CMD) — similar presentation but without >90% epicardial constriction; ST depression more common [13-14]
- Esophageal spasm — can mimic angina and respond to NTG; distinguish with pH/manometry
- Kounis syndrome — allergic coronary spasm; look for concurrent allergic reaction [7]
- Early repolarization — benign STE pattern, no symptoms
9. Past Medical History
- Prior episodes of rest angina, especially nocturnal
- History of MINOCA (MI with nonobstructive coronary arteries) — vasospasm accounts for ~20% of MINOCA cases [5]
- Prior cardiac catheterization results (normal or nonobstructive coronaries)
- History of migraines or Raynaud phenomenon (associated vasomotor disorders)
- Prior arrhythmias, syncope, or cardiac arrest
- Chronic illnesses: hypertension, dyslipidemia, diabetes (contribute to endothelial dysfunction)
10. Physical Exam
- Often entirely normal between episodes
- During an acute episode:
- Diaphoresis, pallor, distress
- Tachycardia or bradycardia
- Hypotension (if severe spasm with hemodynamic compromise)
- New S3 or S4 gallop, transient mitral regurgitation murmur
- Signs of heart failure if prolonged ischemia
- Look for signs of substance use (nasal septal perforation, track marks)
- Assess for signs of connective tissue disease or vasculitis
11. Lab Studies
- Troponin (high-sensitivity preferred): usually negative if spasm resolves quickly; may be mildly elevated with prolonged spasm or MINOCA [15-16]
- BMP: baseline renal function, electrolytes (hypomagnesemia can contribute)
- Magnesium level — low magnesium may predispose to spasm [2]
- Lipid panel — for statin initiation and risk stratification
- Urine drug screen — critical to identify cocaine/amphetamine use [5]
- CBC, BNP — rule out anemia, heart failure
- CRP/ESR — if inflammatory etiology suspected
12. Imaging
- Coronary angiography — recommended (Class I) in patients with episodic chest pain and transient STE to rule out obstructive CAD [1-2]
- Spasm may occur spontaneously during catheterization, aiding diagnosis [1]
- Catheter-induced spasm is NOT diagnostic of vasospastic disease [1]
- Echocardiography — assess LV function; may show transient wall motion abnormalities during spasm [1]
- CCTA — can identify nonobstructive plaque and myocardial bridging but cannot detect functional vasospasm [17]
- Imaging is generally unnecessary between episodes if diagnosis is established
13. Special Tests
- Provocative testing (Class IIb, AHA/ACC) — when clinical criteria and noninvasive testing fail to establish diagnosis [2][18]
- Intracoronary acetylcholine or ergonovine during angiography
- Positive test: >90% vasoconstriction + reproduction of chest pain + ischemic ECG changes [13]
- Requires temporary pacemaker placement [13]
- Contraindicated in high-grade obstructive stenosis (Class III) [1]
- Continuous ECG (Holter) monitoring — to capture transient STE during spontaneous episodes; recording during multiple episodes improves sensitivity [1]
- Hyperventilation test and cold pressor test — noninvasive provocative options [2]
- Exercise stress testing — one-third show STE, one-third show ST depression, one-third normal; results may not be reproducible and are more often positive in early morning [1]
14. ECG
- Hallmark: Transient ST-segment elevation in the distribution of the spasming artery, resolving when pain abates [1]
- Reciprocal ST depressions may be present [6]
- ST depression instead of elevation if collateral flow is available [7]
- Arrhythmias during episodes: polymorphic VT, VF, high-degree AV block, asystole [6-7]
- Lambda wave pattern — STE with a distinctive morphology in inferior and anterolateral leads; high-risk marker for lethal arrhythmias [6]
- Between episodes: ECG is typically normal
- Serial ECGs are essential — a single normal ECG does not exclude the diagnosis
15. Assessment
Prinzmetal angina is a potentially life-threatening condition that is frequently underdiagnosed because ECG changes are transient and coronary arteries may appear normal on angiography. Key clinical pearls:
- Typical presentation: young(er) patient, smoker, rest angina in early morning hours, dramatic NTG response
- Atypical presentations: exercise-induced (variable threshold), ST depression instead of elevation, asymptomatic ischemia
- Prognosis is generally favorable with treatment in patients without obstructive CAD; worst prognosis when superimposed on obstructive CAD [2]
- Complications: MI (5–10%), fatal arrhythmias, sudden cardiac death [4][7]
- 5–10% of patients experience life-threatening arrhythmias from severe ischemia [4]
16. Treatment Plan
Acute management (ED)
- Sublingual NTG 0.4 mg — repeat every 5 min × 3 doses; typically provides rapid relief [1]
- IV NTG infusion if refractory to sublingual NTG
- Continuous cardiac monitoring
- Avoid beta-blockers [1][10]
- If spasm identified during catheterization: intracoronary NTG 0.3 mg [1]
Chronic management
- CCB at moderate-to-high dose — first-line (Class I) [1-2][14]
- Sublingual NTG as needed for breakthrough episodes
- Statin — for endothelial function and risk modification (Class I) [2]
- Long-acting nitrate — add if CCB alone insufficient; use with nitrate-free interval to avoid tolerance [14]
- Refractory: dual CCB therapy (dihydropyridine + non-dihydropyridine) [1][8]
- Smoking cessation — mandatory [2]
- Substance abuse cessation — cocaine, amphetamines [5]
- Consider magnesium supplementation [2]
- Aspirin: consider only if coexisting atherosclerotic disease; may worsen spasm in pure vasospastic angina [5]
17. Disposition
Admit if
- New-onset transient STE with chest pain (must rule out STEMI)
- Troponin elevation
- Arrhythmias (VT, VF, high-degree AV block) during episode [6]
- Syncope or hemodynamic instability
- Refractory chest pain despite NTG
- Need for coronary angiography
Observation
Discharge considerations
- Known diagnosis, typical episode, rapid resolution with NTG, normal troponin, stable on CCB therapy
- Ensure cardiology follow-up is in place
Consult cardiology for all new presentations and for provocative testing consideration [2][18]
18. Follow Up / Return Precautions
- Cardiology follow-up within 1–2 weeks for new diagnoses; sooner if medication titration needed
- Outpatient coronary angiography if not performed during admission
- Return immediately for: chest pain lasting >15 minutes unresponsive to NTG, syncope, palpitations with lightheadedness, shortness of breath at rest
- Counsel on strict smoking cessation and avoidance of all vasoconstrictive substances [2]
- Carry sublingual NTG at all times
- Expected course: most patients respond well to CCB therapy; disease activity may wax and wane; long-term prognosis is favorable with treatment adherence in the absence of obstructive CAD [2]
- Medication compliance is critical — absence of CCB therapy is an independent determinant of cardiovascular events [8]
References
1. 2011 ACCF/AHA Focused Update Incorporated Into the ACC/AHA 2007 Guidelines for the Management of Patients With Unstable Angina/Non-St-Elevation Myocardial Infarction: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines Developed in Collaboration With the American Academy of Family Physicians, Society for Cardiovascular Angiography and Interventions, and the Society of Thoracic Surgeons. — Wright RS, Anderson JL, Adams CD, et al. Journal of the American College of Cardiology. 2011.
2. 2014 AHA/ACC Guideline for the Management of Patients With Non-St-Elevation Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. — Amsterdam EA, Wenger NK, Brindis RG, et al. Journal of the American College of Cardiology. 2014.
3. Coronary Spasm. — Geist M, Tarchitzky D. The New England Journal of Medicine. 2002.
4. Ischemic Heart Disease in Young Women: JACC Review Topic of the Week. — Minissian MB, Mehta PK, Hayes SN, et al. Journal of the American College of Cardiology. 2022.
5. Causes, Angiographic Characteristics, and Management of Premature Myocardial Infarction: JACC State-of-the-Art Review. — Rallidis LS, Xenogiannis I, Brilakis ES, Bhatt DL. Journal of the American College of Cardiology. 2022.
6. A Distinctive Pattern With Coexisting Malignant Arrhythmias. — Wang G, Zhao N, Zhang D. JAMA Internal Medicine. 2025.
7. Update to Practice Standards for Electrocardiographic Monitoring in Hospital Settings: A Scientific Statement From the American Heart Association. — Sandau KE, Funk M, Auerbach A, et al. Circulation. 2017.
8. Contemporary Diagnosis and Management of Patients With Myocardial Infarction in the Absence of Obstructive Coronary Artery Disease: A Scientific Statement From the American Heart Association. — Tamis-Holland JE, Jneid H, Reynolds HR, et al. Circulation. 2019.
9. Emerging Pathway to a Precision Medicine Approach for Angina With Nonobstructive Coronary Arteries in Women. — Hosadurg N, Watts K, Wang S, et al. JACC. Advances. 2024.
10. Comprehensive Management of ANOCA, Part 2-Program Development, Treatment, and Research Initiatives: JACC State-of-the-Art Review. — Smilowitz NR, Prasad M, Widmer RJ, et al. Journal of the American College of Cardiology. 2023.
11. RNF213 Variants, Vasospastic Angina, and Risk of Fatal Myocardial Infarction. — Hikino K, Koyama S, Ito K, et al. JAMA Cardiology. 2024.
12. Computed Tomographic Angiography-Verified Myocardial Bridge and Invasive Angiography-Verified Left Anterior Descending Coronary Artery Vasospasm. — Kawai H, Ohta M, Motoyama S, et al. JACC. Cardiovascular Interventions. 2020.
13. Comprehensive Management of ANOCA, Part 1-Definition, Patient Population, And Diagnosis: JACC State-of-the-Art Review. — Samuels BA, Shah SM, Widmer RJ, et al. Journal of the American College of Cardiology. 2023.
14. 2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines. — Virani SS, Newby LK, Arnold SV, et al. Journal of the American College of Cardiology. 2023.
15. 2022 ACC Expert Consensus Decision Pathway on the Evaluation and Disposition of Acute Chest Pain In the Emergency Department: A Report of the American College of Cardiology Solution Set Oversight Committee. — Kontos MC, de Lemos JA, Deitelzweig SB, et al. Journal of the American College of Cardiology. 2022.
16. 2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. — Rao SV, O'Donoghue ML, Ruel M, et al. Journal of the American College of Cardiology. 2025.
17. Evolving Management Paradigm for Stable Ischemic Heart Disease Patients: JACC Review Topic of the Week. — Boden WE, Marzilli M, Crea F, et al. Journal of the American College of Cardiology. 2023.
18. Acute Coronary Syndromes in Premenopausal Women: A Scientific Statement From the American Heart Association. — Kovacic JC, Reynolds HR, Alasnag M, et al. Circulation. 2026.